This application is based on application No. 318541/1997 filed in Japan, the contents of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming method so adapted that an electrostatic latent image is formed on the surface of an image carrying member, a non-conductive release agent is applied to the surface of the image carrying member, and ink is brought into contact with the surface of the image carrying member thus having the electrostatic latent image formed thereon and the release agent applied thereto, to form an ink image corresponding to the electrostatic latent image on the surface of the image carrying member, and more particularly, to an image forming apparatus and an image forming method characterized in that the ink adheres on a portion of the electrostatic latent image formed on the surface of the image carrying member, while the ink is prevented from adhering on the portion having no electrostatic latent image formed thereon, so that a good image which has a sufficient image density and was not fogged is obtained.
2. Description of the Related Art
Conventionally, an image forming apparatus so adapted as to form an electrostatic latent image on the surface of an image carrying member, develop the electrostatic latent image, and then transfer the electrostatic latent image on a recording medium such as paper, to form an image on the recording medium has been conventionally used, as represented by an electrophotographic copying machine.
Known as one of such an image forming apparatus utilizing an electrophotographic system is one using a liquid developer obtained by dispersing colored resin particles (toner particles) in a carrier liquid in order to develop an electrostatic latent image, as disclosed in JPA-7-271107.
The liquid developer used in the electrophotographic apparatus is generally obtained by dispersing charged toner particles in an insulating carrier liquid. The toner particles are selectively consumed from the liquid developer as an image is formed. When the liquid developer is used, therefore, the density of the toner particles in the carrier liquid must be managed. The management is troublesome. Further, a large part of the carrier liquid is repeatedly used, so that the liquid developer is liable to be degraded.
Furthermore, in the electrophotographic apparatus thus using the liquid developer, when the image is formed on a recording medium such as copying paper, a fixing device or the like for fixing a ton er image transferred onto the recording medium is required. Therefore, the apparatus is complicated and is increased in size, for example.
Conventionally, an image forming apparatus so adapted that an electrostatic latent image is formed on the surface of an image carrying member, a non-conductive release agent is applied to the surface of the image carrying member, ink is brought into contact with the surface of the image carrying member thus having the electrostatic latent image formed thereon and the non-conductive release agent applied thereto, the ink is made to adhere to a portion, where the electrostatic latent image is formed, on the surface of the image carrying member, to from an ink image corresponding to the electrostatic latent image on the surface of the image carrying member, and the ink image is transferred onto a recording me dium from the surface of the image carrying member, to form an image has been proposed, as disclosed in U.S. Pat. No. 4,272,599.
In the image forming apparatus, however, there are some problems. For example, the ink does not sufficiently adhere on the portion of the electrostatic latent image formed on the surface of the image carrying member, so that the density of the formed image is decreased, and voids are created in the formed image. Contrary to this, the ink also adheres to a portion having no electrostatic latent image formed thereon in the image carrying member, so that the formed image is fogged.